Morris Minor Owners Club

Fitted fully reconditioned heads to my V8 minor with disastrous results. I now need a new engine.
The V8 forum guys are a bit stumped on why it happened too - never seen it happen.
Thread in V8 forum:

http://www.v-8.org.uk/forum/viewtopic.php?t=524

Check out the pics:


Before I started






One off




No 1 N/S






No 4 N/S





No 2 N/S - undamaged




Pistons




No 1 N/S




Head




Casting Number of 'Vitesse' head



Casting number of my spare SD1 head




The 3 heads - Vitesse, SD1 and P6 - left to right






Vitesse and SD1 head - note combustion chamber difference







SD1 and P6 head - similar combustion chambers:



Close ups of combustion chambers:

Vitesse





SD1





P6





I think that the 'Vitesse' heads had a much smaller combustion chamber, causing massive detonation, but then, why not on all cylinders. Engine was never overheated and wasn't driven - still a mystery to me.
I'm going to build up a spare SD1 engine I have, use the new valves and springs from the damaged head, and the cam from the P6 engine and see how that goes - unless someone has another suggestion.

Pete

Afraid so - detonation damage! Must have had massive compression ratio - the starter must have struggled!!

This is the funny thing - car only did 1 mile on road and ran in total (over a few days) for about an hour ticking over in my drive as I investigated problems (investigating lifter pre load). Turned over fine on starter too.
Rover guys unsure what problem has been as the cylinder head was only surfaced slightly, and it was a lowish compression engine which ran perfectly before (there is a lesson here, but I never learn).
I'm off to remove other head now, then the engine, and will remove my new valves and springs from the head for reuse (hope there ok)

Pete

Took a couple of valves out today to check them, and also removed other head, plus further dismantling prior to removal to skip.
Pistons definately are not too high in block, but I still think the combustion chambers in heads are unusual - causing detonation. Funny thing is, engine turned over as normal - wouldn't expect this if comp ratio too high.

Valves Removed













As I thought - number 3 on O/S








No. 2 O/S showing start of problem



Pistons




No 2 again - just starting to break up




N/s




O/S






Ready for coming out front end removed

D'you think you could make the pics a bit bigger filesize wise? Only my coffee machine hadn't quite finished before the page loaded ;)

Could there be a fuelling issue? It's not just compression, it's how much motion potion is going in to - I wonder if there's been starvation for some reason, and the inlet design has concentrated the effects?

Damage wasn't done on the road - but ticking over in my drive.

Pete

Funny it's not there in all the cylinders. Could there have been a foreign body drawn it and bouncing around ? Looks like a crack in one of the chamber shots too - but water ingress wouldn't do that - or would it ??

That's grim, Pete. Really sorry - must have been a heck of a shock.

I'm very ignorant but trying to learn, as you know - can you tell me what order the chambers of a V8 fire in? I assume they fire in sequence, and that none overlap?

I'm having trouble following the story, as I'm on a dial-up connection and my machine refuses to load all the photos, but I'm interested as well as horrified at what has happened to your engine.

bw

wibble

ps have just noticed (more photos have loaded) the small sausage-shaped mark on the bottom (of photo) of no 2 OS - both on the piston and on the head. Is that a sign of how the problem started? Is it a recess in both sides of the "sandwich"?

I think I've located the problem. My engineer mate came up tonight and went over the engine with a fine toothcomb and discovered the following embedded in cylinder 3 O/S. It is steel, but I don't know what It's been, and how come 3 cylinders have been affected - same pattern in each. I removed carb from inlet, but nothing that i can see has dropped off it - a mystery.


Pete


pics

Whoops Still, congrats on finding it, and good luck next time around

they are not locating dowels of some sorts are they?

You can borrow my spare 803 if you want Pete

Onne, who knows what it is - 803 is looking good at the moment

Pete

Locating dowels all present and correct.

Pete

Getting a replacement 3.9 litre one on Monday. Don't really know condition other than it is a runner - may have to rebuild it, but it will then be good.

Pete

If it runs I would leave it well alone - look what happened when you 'rebuilt' the last one !!

That was my first engine disaster in 35 years - still can't figure it out.
I'll have a good look at the engine I'm getting and will decide my course of action. Rover V8's tend to give signs that they need rebuilt, but can still run well despite being worn out.

Pete

goood luck with the new engine, pete, have fun, it's time the tide turned eh

Got the engine for a really good price, so tide has turned (for the time being)
Came about due to chance conversation on local Bike Club website.
I'll post pics of the fitting process.

Pete

That was a bit scathing BMC!

Glad you've got something sorted out Pete. The 'before' pic of the engine bay looks very nice indeed.